After HIV has infected the body, there are certain symptoms during the acute phase, usually around 2-4 weeks after HIV infection occurs. This is when some people have clinical symptoms due to the replication of HIV in the body, which leads to damage to the immune system. The most common symptoms are fever, general malaise, nausea, vomiting, headache, joint pain, diarrhea, swollen lymph nodes and so on. In fact, most of these symptoms are mild and can resolve on their own in about 1-3 weeks, and HIV RNA and P24 antigen can be detected in the patient’s blood during this period. The diagnosis can be confirmed by these tests, after which the patient enters a long asymptomatic period, which takes about 6-8 years. Eventually, the patient will enter the AIDS phase, during which he or she will have many symptoms, such as persistent fever, night sweats, diarrhea, weight loss, and symptoms of infection in various organ systems.